Scientists say one effect of Earth’s warming is more frequent extreme weather events, including drought and intense bursts of rainfall from an atmosphere that now holds more moisture than in the past.
Intense dryness followed by intense wetness means massive amounts of water moving through the soil, bringing farm chemicals like nitrogen with it, Glisan said.
And a warmer atmosphere is thawing Earth’s polar regions and causing more of those winter flip-flops from frigid polar air to warmer, less snowy weather, he said.
Even though some storms brought a lot of snow this winter, it didn’t stay on the ground for very long. Instead, snow insulated the soil in some areas from freezing too deep, and a quick thaw let melting snow, followed by pounding rain, travel down through the soil and eventually into streams.
Where the ground isn’t consistently frozen, nutrients aren’t as “locked in” to the soil frost.
“In central and southern Illinois, we’ve always dealt with a sort of ephemeral freeze-thaw, freeze-thaw process. What we’re seeing is that’s really tracking farther north,” said Trent Ford, Illinois’ state climatologist.
A field used for corn silage on Blue Spruce Farm is pictured on March 24 in Bridport, Vt.
Amanda Swinhart, Associated Press
Stakes are high for low-income and rural communities
Nitrate pollution is a big problem for low-income, rural residents across the United States, said Samuel Sandoval Solis, a professor at the University of California-Davis and an extension specialist in water resources management.
While some communities already have the infrastructure to manage nitrate levels in drinking water, like filtration systems, many others don’t. Around 15% of the U.S. population relies on drinking water wells that are private, according to the U.S. Geological Survey. Nitrates can seep into those wells.